The present invention relates to a machine for orienting containers made of plastic material.
In particular, the machines in question pertain to the sector of automatic filling or bottling plants and perform the function of receiving the containers or bottles positioned at random and orient them arranging them in rows on a conveyor with their opening facing upwards. Different types of orienting machines are known, and in particular the present invention refers to an orienting machine as described in patent No. IT 1253395 in the name of the same Applicant.
This machine has a fixed cylindrical structure with vertical axis which encloses in order a rotating cylinder and a fixed conical structure, both coaxial relative to said cylindrical structure.
In the annulus between the rotating cylinder and the maximum radial extension of the conical structure, some elevators are inserted, mounted on the inner wall of the rotating cylinder and integral therewith in rotation about the vertical axis.
Such elevators are engaged in guides integral with the rotating cylinder so as to be able to translate vertically relative thereto. The elevators receive the containers positioned horizontally and transfer them from the lower edge of the conical structure to the upper edge of the cylinder, where they are offloaded inside receptacles integral with the outer wall of the rotating cylinder.
Below the receptacles is provided a fixed ring, integral with the cylindrical structure, provided with one or more interruptions which constitute the offloading point of the containers themselves. When the container arrives in proximity to one of such interruptions, its support is removed, so the container drops internally to drop channels positioned underneath the receptacles.
The shape of the receptacle allows in this phase to upset the container whilst maintaining its opening upwards.
The alternating vertical translation motion is imparted to the elevators by means of radial arms positioned inferiorly to the fixed conical structure, rotating about the axis of rotation of the cylinder and operatively connected to a fixed cam. Such cam is shaped in such a way as to raise and lower the arms and consequently the elevators in positions determined by the trajectory of rotation of the rotating cylinder, and in particular to raise them upstream of each interruption of the fixed ring, according to the direction of rotation of the cylinder.
If during the loading of the containers on the elevators and their positioning into the receptacles, the containers are not arranged correctly, suitable means, such as blowing nozzles, throw the containers back onto the conical structure.
Consequently, the corresponding receptacles remain empty and they will be loaded during the subsequent turn, in the case of machines that offload once, or in the second segment of the fixed ring, in the case of machines that offload twice.
This entails that during the loading phase in question, the maximum productivity allowed by the machine and corresponding to the number of receptacles which can be filled, is not reached.
The aim of the present invention is to eliminate the aforesaid drawbacks making available a machine for orienting containers which allows to increase the degree of filling of the receptacle for each loading phase, avoiding leaving receptacles empty due to erroneous positions of the containers.
Said aims are fully achieved by the machine for orienting containers of the present invention, which is characterised by the contents of the claims set out below and in particular in that the fixed cam commanding the elevators comprises, for each interruption for offloading the containers of the support ring, at least two portions defining the upwards run of an elevator, said portions being positioned upstream of said interruption according to the direction of rotation of the rotating cylinder.
Briefly, the cam is shaped so that before the offloading position the elevator performs two or more upwards runs.